US Patent 7269465 Control system for controlling safety-critical processes

There is provided a control system for controlling safety-critical processes that includes a fieldbus, a bus master for controlling a communication via the fieldbus, at least one signal unit for linking to at least one of the safety-critical processes, and a first control unit for controlling at least one of the safety-critical processes. The bus master and the at least one signal unit are connected to one another via the fieldbus to provide communication between at least one signal unit and the bus master. The at least one signal unit and the first control unit have safety-related devices. Failsafe communication is provided to control at least one of the safety-critical processes, and the first control unit is connected to the bus master independently of the fieldbus.